An adaptive mid-urethral suspension system based on variable stiffness structure

Abstract

The application relates to a self-adaptive mid-urethral suspension system based on a variable stiffness structure, and belongs to the technical field of medical devices. The suspension system comprises a sling body, the sling body is divided into a support area, an anchoring area and a transition area, and a silica gel pad is fixedly arranged on the support area; the initial stiffness of the support area is 0.1-0.8 N / mm, the load stiffness is 0.2-12.0 N / mm, the initial stiffness of the anchoring area is 0.05-0.4 N / mm, the load stiffness is 0.5-2.5 N / mm, the initial stiffness of the transition area is 0.08-0.5 N / mm, and the load stiffness is 1.0-5.0 N / mm. Through the design, the sling body is soft in a resting state to reduce tissue compression, and the stiffness is dynamically increased when abdominal pressure is increased to provide effective support, and the sling body can be self-adaptively adjusted. The application also provides a customization system, which comprises a data acquisition module, a mechanical modeling module, a data output module and a weaving module, and is used for generating a matched sling according to the pelvic floor biomechanics data of a patient.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to an adaptive mid-urethral suspension system based on a variable stiffness structure. Background Technology

[0002] Stress urinary incontinence (SUI) is a common complication after radical prostatectomy in men, and it can significantly impact a patient's quality of life. Under-urethral sling surgery, due to its minimally invasive nature, relative simplicity, and proven efficacy, has become a common treatment for moderate to severe stress urinary incontinence following prostatectomy. This procedure involves placing a tension-free sling under the bulbar urethra, providing effective pelvic fascial support when abdominal pressure increases, thereby compressing the urethra to restore urinary control.

[0003] For patients with moderate to severe internal sphincter deficiency (ISD), their sphincter itself has lost its effective active closure ability, and urinary continence relies on the dynamic support of a sling under external force. Currently, commonly used male urethral slings are typically made of a single type of woven material, such as Advance products, which are woven slings with fixed stiffness. This uniform stiffness design cannot adapt to dynamic changes in abdominal pressure, resulting in limited urinary continence in patients with moderate to severe internal sphincter deficiency. Summary of the Invention

[0004] To address the above issues and overcome the shortcomings of existing technologies, this invention provides an adaptive mid-urethral suspension system based on a variable stiffness structure, comprising a sling body, wherein the sling body includes:

[0005] The support area is located in the middle of the sling body; the initial stiffness of the support area is 0.1-0.8 N / mm, and the load stiffness is 0.2-12.0 N / mm; a silicone pad is fixedly installed on the surface of the support area near the urethra;

[0006] Anchoring zones are symmetrically arranged on both sides of the support zone; the initial stiffness of the anchoring zones is 0.05-0.4 N / mm, and the load stiffness is 0.5-2.5 N / mm.

[0007] A transition zone is located between the support zone and the anchoring zone. The initial stiffness of the transition zone is 0.08-0.5 N / mm, and the load stiffness is 1.0-5.0 N / mm.

[0008] The stiffness of the transition zone is between that of the support zone and the locking zone.

[0009] More preferably, the diameter of the monofilament constituting the support area is 0.15-0.25 mm, and its material is one of polypropylene, polyvinylidene fluoride, or polyester; the support area has a high-density woven structure with a weaving density of 35-50 stitches / 10cm and a mesh area of ​​2.0-3.0 mm². 2 .

[0010] More preferably, the diameter of the monofilament constituting the anchoring area is 0.06-0.12 mm, and its material is one or a mixture of two of polypropylene, polylactic acid-coated polypropylene composite material, or polyvinylidene fluoride; the anchoring area has a low-density woven structure with a weaving density of 20-30 stitches / 10cm and a mesh area of ​​3.0-4.5 mm². 2 .

[0011] More preferably, the diameter of the monofilament constituting the transition zone is 0.10-0.18 mm, and its material is one of polypropylene, polyvinylidene fluoride, polypropylene and polylactic acid composite, or polypropylene and polyglycolic acid composite; the transition zone has a gradually decreasing density braided structure, with the braiding density gradually decreasing by 5-15 stitches / 10cm along the direction from the support zone to the anchoring zone, and the mesh area ranging from 0.5-2.0 mm². 2 The change gradually increases, and the weaving density and mesh area at any position in the transition zone are between or equal to the corresponding parameters of the support zone and the anchoring zone.

[0012] More preferably, the diameter of the monofilament constituting the support area is 0.18-0.25 mm, and its material is polypropylene or polyvinylidene fluoride; the weaving density of the support area is 38-45 stitches / 10cm, and the mesh area is 2.0-2.5 mm². 2 .

[0013] More preferably, the diameter of the monofilament constituting the anchoring area is 0.10 mm, and its material is one of polypropylene or polypropylene composite material coated with polylactic acid; the anchoring area has a low-density braided structure with a braiding density of 25-30 stitches / 10cm and a mesh area of ​​3.0-4.0 mm². 2 .

[0014] More preferably, the diameter of the monofilament constituting the transition zone is 0.14-0.18 mm, and its material is one of polypropylene and polylactic acid composite material or polypropylene and polyglycolic acid composite material; the transition zone has a gradually decreasing density braided structure, with the braiding density gradually decreasing by 8-15 stitches / 10cm along the direction from the support zone to the anchoring zone, and its mesh area ranging from 0.8-2.0 mm². 2 The amount of change gradually increases.

[0015] More preferably, the distal end of the anchoring area is provided with a widening structure, and the widening structure has a channel for surgical instruments to pass through.

[0016] Another aspect of the present invention provides a method for fabricating an adaptive mid-urethral suspension system based on a variable stiffness structure, comprising:

[0017] The preparation method includes a personalized customization step and a sling body manufacturing step;

[0018] The personalization process includes:

[0019] Acquire target patient data;

[0020] Based on the data, a mechanical model of the patient is constructed, and the stiffness distribution parameters of the required sling body are calculated.

[0021] The weaving parameters of the sling body are determined based on the stiffness distribution parameters. The weaving parameters include the monofilament diameter, weaving density, and mesh area of ​​the support area, anchoring area, and transition area, respectively.

[0022] The steps for manufacturing the sling body include: preparing the sling body using a variable weaving process according to the weaving parameters.

[0023] More preferably, the manufacturing steps of the sling body include:

[0024] Prepare monofilaments: According to the braiding parameters, prepare monofilaments to form the support zone, anchoring zone, and transition zone respectively. The monofilaments forming the support zone have a diameter of 0.15-0.25 mm and are made of polypropylene, polyvinylidene fluoride, or polyester. The monofilaments forming the anchoring zone have a diameter of 0.06-0.12 mm and are made of polypropylene, polypropylene composite material coated with polylactic acid, or polyvinylidene fluoride, or a mixture of two of these materials. The monofilaments forming the transition zone have a diameter of 0.10-0.18 mm and are made of polypropylene, polyvinylidene fluoride, polypropylene and polylactic acid composite, or polypropylene and polyglycolic acid composite.

[0025] Setting up the knitting equipment: Install the prepared monofilaments for each area onto the warp knitting machine, set the knitting program so that the knitting density of the support area is 35-50 stitches / 10cm and the mesh area is 2.0-3.0 mm. 2 The weaving density of the anchoring area is 20-30 stitches / 10cm, and the mesh area is 3.0-4.5 mm. 2 The transition zone, along the direction from the support zone to the anchoring zone, gradually decreases in knitting density by a variation of 5-15 stitches / 10cm, with a mesh area ranging from 0.5-2.0 mm. 2The change gradually increases, and the weaving density and mesh area at any position in the transition zone are between the corresponding parameters of the support zone and the anchoring zone;

[0026] Weaving: Start the warp knitting machine to weave. During the weaving process, the machine automatically switches between monofilaments of different diameters according to the program to obtain a continuous suspender fabric.

[0027] Post-processing: The suspender fabric is heat-set, cleaned, and dried.

[0028] Cutting and shaping: The post-processed suspender fabric is cut into the preset size, silicone pads are fixedly installed in the support area, and a widened structure and channel are formed at the far end of the anchoring area. After sterilization, the finished suspender body is obtained.

[0029] Compared with existing technologies, this invention has the following beneficial effects: By designing the sling body with a support zone, anchoring zone, and transition zone with differentiated stiffness, this invention enables the sling's mechanical properties to more effectively adapt to stress urinary incontinence caused by moderate to severe intrinsic sphincter defects. Specifically, the initial stiffness of the support zone is set at 0.1-0.8 N / mm, remaining soft and without significant pressure at rest, reducing continuous stimulation of the tissues surrounding the bulbar urethra. When abdominal pressure increases, the load stiffness of the support zone can increase to 0.2-12.0 N / mm, dynamically increasing with the load, providing effective support for the bulbar urethra, thereby achieving effective urinary control under high abdominal pressure conditions such as coughing and sneezing. The transition zone smoothly transitions the stiffness between the support zone and the anchoring zone, allowing the sling to maintain good support performance while avoiding tissue stress concentration caused by abrupt changes in stiffness between regions. The anchoring zone adopts a lower stiffness design, making it softer, which helps reduce the interaction with the soft tissue at the fixation point, reduces the risk of local inflammatory reactions, and improves the long-term implantation compatibility of the sling. This variable stiffness structure design makes the sling body more adaptable to dynamic changes in abdominal pressure. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the sling body structure of the present invention.

[0031] Figure 2 This is a schematic diagram of the overall structure of the present invention.

[0032] Figure 3 This is a schematic diagram of the monofilament structure of the present invention.

[0033] Figure 4 This is a flowchart of the customized system of the present invention.

[0034] Explanation of the labels in the diagram:

[0035] 1. Sling body; 2. Support area; 3. Transition area; 4. Anchoring area; 5. Widened structure; 6. Channel; 7. Silicone pad. Detailed Implementation

[0036] The present invention will now be described in further detail with reference to embodiments. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit the invention.

[0037] To achieve the aforementioned objectives, this invention provides an adaptive mid-urethral suspension system based on a variable stiffness structure. Its overall technical solution, as described in the embodiments of this application, mainly includes the following core technical elements: a sling body 1 with zoned stiffness characteristics (including a support zone 2, an anchoring zone 4, and a transition zone 3), a silicone pad 7 disposed on the support zone 2, differentiated weaving structures and material compositions for each zone, and a matching individualized customization system. These technical elements work together to constitute the overall technical solution of this invention.

[0038] Terminology definition:

[0039] To make the technical solution of this invention clearer, the key terms used in this invention are first defined and explained:

[0040] Strain: refers to the relative deformation of a sling under tensile load, defined as the ratio of displacement to the original gauge length, expressed as a percentage. In this invention, the strain range corresponds to physiological states: 0-5% strain range corresponds to the resting state, and 5%-15% strain range corresponds to states of high abdominal pressure such as coughing and sneezing.

[0041] Stiffness refers to the ability of a sling to resist tensile deformation. It is defined as the slope of the force-displacement curve within a specified load range, and is measured in Newtons per millimeter (N / mm). A higher stiffness value indicates a "harder" sling that is less prone to deformation; a lower stiffness value indicates a "softer" sling that is more easily deformed.

[0042] Initial stiffness: refers to the ability of a sling to resist tensile deformation within the 0-5% strain range. It is defined as the slope of the force-displacement curve within this strain range, and the unit is Newtons per millimeter (N / mm), denoted by the symbol K. initial This parameter reflects the degree of pressure the sling exerts on surrounding tissues in a resting state. The lower the initial stiffness, the softer the sling, and the lower the risk of foreign body sensation and tissue erosion after implantation.

[0043] Load stiffness: refers to the ability of a sling to resist tensile deformation within a strain range of 5%-15%, denoted by the symbol K. load This parameter reflects the sling's ability to resist deformation and support the urethra when abdominal pressure increases. Higher load stiffness means stronger support provided by the sling during exertion, resulting in better urinary control.

[0044] Adaptive: In this invention, it specifically refers to the load-dependent stiffness characteristics of the sling, that is, the nonlinear mechanical behavior of the sling's stiffness value as strain increases. It maintains low stiffness (soft, no pressure) at low strain (0-5%), and transforms into high stiffness (rigid, strong support) at high strain (5%-15%).

[0045] like Figure 1-3 As shown, this invention provides an adaptive mid-urethral suspension system based on a variable stiffness structure, comprising a sling body 1. A support zone 2 is located in the middle of the sling body 1, used to support the mid-urethra after implantation, specifically supporting the bulbar urethra and providing urinary control. Anchoring zones 4 are symmetrically arranged on both sides of the support zone 2, used to fix with pelvic fascia tissues (such as the retropubic space, ischiopectine ramus, etc.), anchoring the sling within the body. A transition zone 3 is located between the support zone 2 and the corresponding anchoring zone 4, used to achieve a smooth transition in stiffness from the support zone 2 to the anchoring zone 4. Figure 2 As shown, a silicone pad 7 is fixedly disposed on the side of the support area 2 facing the urethra. After implantation, the silicone pad 7 directly contacts the bulbous urethra, providing cushioning and protection. The length of the support area 2 is 25-35 mm, preferably 28-32 mm; the length of each anchoring area 4 is 40-60 mm, preferably 45-55 mm; the length of each transition area 3 is 10-15 mm, preferably 12-14 mm; the silicone pad 7 has a thickness of 2-4 mm, a width of 10-15 mm, and a length of 20-30 mm.

[0046] This application further provides a method for fabricating an adaptive mid-urethral suspension system based on a variable stiffness structure. This method includes a personalized customization step and a sling body fabrication step. The personalized customization step involves a data acquisition module, a mechanical modeling module, a data output module, and a weaving module, with each module working collaboratively to achieve end-to-end customization from patient data to the final product.

[0047] The data acquisition module collects pelvic floor imaging data from patients using medical imaging equipment, including static high-resolution T2-weighted scans (2 mm slice thickness, 0 mm slice spacing) and dynamic MRI scans (at rest and during Valsalva maneuvers) using a 3.0T MRI scanner, or three-dimensional ultrasound imaging (probe frequency 5-9 MHz) to acquire three-dimensional images of pelvic floor organs. Simultaneously, this module collects urodynamic data from patients using a urodynamic testing device, including parameters such as leakage point pressure, maximum urinary flow rate, and bladder compliance. The leakage point pressure is measured by instilling normal saline into the bladder at a rate of 50 ml / min, and the patient repeatedly coughs when the bladder is full to 200-300 ml, recording the minimum abdominal pressure at which leakage occurs. The acquired raw medical imaging and communication (DICOM) data and urodynamic data files are uniformly transmitted to the biomechanical modeling module via a data interface.

[0048] The mechanical modeling module receives pelvic floor biomechanical data and constructs a finite element mechanical model of the patient's pelvic cavity. First, DICOM data from magnetic resonance imaging or 3D ultrasound is imported into medical image processing software (such as Mimics or 3DSlicer). Through thresholding, region growing, and manual editing, anatomical structures such as the bulbar urethra, urethral sphincter, and anterior rectal wall are sequentially segmented. The segmented 2D contours are then reconstructed into 3D surfaces to generate triangular mesh models of each organ. Subsequently, the reconstructed 3D geometric model is imported into finite element analysis software (such as Abaqus or Ansys), and meshing is performed using tetrahedral or hexahedral elements, with element sizes controlled between 1-3 mm. Based on literature reports and common knowledge in the field, corresponding material properties are assigned to different tissues: the urethra and bladder wall use a hyperelastic Ogden model, with urethral Ogden model parameters β=1 kPa and α=4.7; the bladder wall tensile elastic modulus is in the range of 10–40 kPa, which can be calibrated according to the specific patient's urodynamic examination results. The urethral sphincter was modeled using a transversely anisotropic hyperelastic model with a transverse modulus of 80–200 kPa and a longitudinal modulus of 20–60 kPa. The levator ani muscle was modeled using a transversely isotropic hyperelastic model, taking into account the direction of muscle fibers. The pelvic fascia and ligaments were modeled using linear elastic or hyperelastic models. In the boundary condition settings, the bony structures of the pelvis (pubis, ischium, sacrum) were set as fixed constraints, the attachment points of the levator ani muscle were subject to displacement constraints, contact pairs were set between pelvic floor organs, and the coefficient of friction was set to 0.1–0.3. In terms of load settings, an increasing pressure load was applied to the inner surface of the bladder, gradually increasing from 0 to 100–200 cm H2O (approximately 9.8–19.6 kPa), while a synchronously increasing abdominal pressure load was applied to the abdominal cavity side to simulate states of increased abdominal pressure such as coughing and jumping.

[0049] Based on the finite element model of the component, the mechanical modeling module simulates the urethral closure process under increased abdominal pressure and calculates the required stiffness distribution parameters of the sling. The sling model is embedded into the finite element model, with its position set below the bulbous urethra and both ends fixed to the retropubic space or the ischiopectine ramus. A contact relationship (friction coefficient 0.2) is established between the sling and the urethra. A bisection iterative optimization algorithm is used: the initial stiffness is taken as the midpoint of the range for the search, and the search range is halved in each iteration; convergence is determined when the stiffness difference between two adjacent iterations is < 0.01 N / mm, and the maximum number of iterations does not exceed 50. Specifically, the initial stiffness value of the sling support area 2 is set as a variable (within the range of 0.1-15 N / mm). After applying physiological load, the urethral closure pressure (the difference between the pressure inside the urethra and the bladder pressure) is calculated to determine whether the urethra is effectively closed; if not, the stiffness value is increased and recalculated; if satisfied, the current stiffness value is recorded. Repeat the above process within the 5%-15% strain range to calculate the minimum load stiffness value K required for effective closure of the urethra within this range. load target Simultaneously, the target stiffness of anchoring zone 4 and transition zone 3 was determined according to the zoning design requirements: the initial target stiffness of anchoring zone 4 was set to 0.05-0.4 N / mm, which was less than the initial stiffness of support zone 2; the target stiffness of transition zone 3 was set to be between that of support zone 2 and anchoring zone 4, exhibiting a gradient change. To verify the accuracy of the model, the mechanical modeling module further calibrated the model using the leakage point pressure from the patient's urodynamic data: the bladder pressure was gradually increased in the model, and the simulated leakage point pressure value at the onset of urethral leakage was observed and compared with the actual measured leakage point pressure. If the error between the two exceeded 10%, the model parameters (such as tissue material properties, contact friction coefficient, etc.) were adjusted and recalculated until the simulated value matched the measured value. Finally, the mechanical modeling module output the target initial stiffness values ​​and target load stiffness values ​​for support zone 2, anchoring zone 4, and transition zone 3.

[0050] The data output module connects to the mechanical modeling module and is used to determine the specific weaving parameters of the sling body 1 based on the target stiffness value. This module contains a pre-established "stiffness-weaving parameter" database, covering materials such as polypropylene and polyvinylidene fluoride at different monofilament diameters (0.06-0.25 mm, step size 0.02 mm), weaving densities (20-60 stitches / 10cm, step size 5 stitches / 10cm), and mesh areas (1.5-8.0 mm²). 2 Step size 0.5 mm 2 The measured values ​​of initial stiffness and load stiffness under ( ). The data output module matches the target stiffness value input from the mechanical modeling module with the database: first, it matches support zone 2, and then searches for values ​​that satisfy K. initialtarget and K load targetFor the combination of weaving parameters, prioritize combinations that simultaneously meet both requirements; if both cannot be simultaneously met, use K. load target As the primary objective, K initialtarget For secondary objectives, select the closest combination. Then match anchoring zone 4, and based on the initial stiffness (0.05-0.4 N / mm) and load stiffness requirements of anchoring zone 4, select the corresponding filament diameter (0.06-0.12 mm) and low-density weaving parameters (weaving density 20-30 stitches / 10cm, mesh area 3.0-4.5mm). 2 Finally, transition zone 3 is matched. Based on the parameters of support zone 2 and anchoring zone 4, the gradient parameters of transition zone 3 are generated by linear interpolation to ensure that the knitting density change is within the range of 5-15 stitches / 10cm and the mesh area change is within 0.5-2.0 mm. 2 Within the specified range, the data output module organizes the determined weaving parameters into a standard format output file, including the monofilament diameter, weaving density, mesh area, material selection, total sling length, and length of each area (support area 25-35 mm, transition area 10-15 mm, anchoring area 40-60 mm), and transmits it to the weaving module via industrial Ethernet or USB interface.

[0051] Table 1. Database Example (using polypropylene as an example)

[0052] Single filament diameter (mm) Knitting gauge (needles / 10cm) <![CDATA[Mesh area (mm 2 )]]> <![CDATA[K initial (N / mm)]]> <![CDATA[K load (N / mm)]]> 0.10 20 5.5 0.08±0.01 0.5±0.05 0.10 25 4.0 0.12±0.02 1.0±0.10 0.10 30 3.0 0.15±0.02 1.5±0.12 0.18 38 2.2 0.25±0.03 2.0±0.20 0.18 42 2.0 0.30±0.03 2.5±0.25 0.20 40 2.8 0.5±0.05 8.0±0.80 0.22 45 2.0 0.30±0.03 5.0±0.50 0.25 40 2.5 0.7±0.07 12.0±1.2

[0053] Note: The data in Table 1 are based on actual measurements with a gauge length of 30 mm and strain ranges of 0–5% (initial stiffness) and 5%–15% (load stiffness), with n=5 parallel samples in each group.

[0054] The knitting module is connected to the data output module to receive knitting parameters and prepare the strap body 1 using a variable knitting process. This module uses a multi-bar warp knitting machine (Karl Mayer HKS series) for knitting. First, based on the parameters provided by the data output module, a program is set in the warp knitting machine's control system: the warp feed amount of each bar is calculated and determined according to the knitting density requirements; the needle bed traverse program is set according to the mesh shape (rhomboid or hexagonal) and size; the monofilament switching program automatically switches monofilaments of different diameters during knitting according to area changes (e.g., switching from 0.18 mm in support zone 2 to 0.14 mm in transition zone 3, and then to 0.08 mm in anchoring zone 4); for transition zone 3, a linear change program for the knitting density from the initial value to the final value is set, with the rate of change calculated and determined based on the gradient requirements (e.g., 10 stitches per centimeter / 10cm) and the length of transition zone 3. Then, prepare medical-grade monofilaments of the appropriate diameter according to the weaving parameters: For support zone 2, the monofilament is made of polypropylene or polyvinylidene fluoride, with a diameter of 0.15-0.25 mm. The monofilament needs to be pre-heat-set to form a crimped structure (treatment conditions: temperature 120℃, stretch ratio 1.5, heat preservation for 30 minutes); for transition zone 3, prepare polypropylene monofilaments and absorbable material monofilaments according to the composite scheme, with a gradual change in diameter of 0.10-0.18 mm; for anchoring zone 4, use polypropylene, polylactic acid-coated polypropylene composite material, or polyvinylidene fluoride, with a diameter of 0.06-0.12 mm. Install the prepared monofilaments onto the corresponding yarn frames of the warp knitting machine, ensuring uniform tension before starting the machine for weaving. During the weaving process, monitor the weaving density, mesh size, and monofilament diameter in real time to ensure the gradual change process meets the requirements. After weaving, a continuous suspender fabric is obtained. After post-treatment (heat setting, washing, drying), cutting (total length 100-150mm), fixing silicone pads 7 on support area 2, forming a widened structure 5 and channel 6 at the far end of anchoring area 4, sterilization and packaging, a personalized suspender body 1 is obtained.

[0055] Mechanical performance test of sling body:

[0056] The mechanical properties of the sling body 1 were tested using a universal testing machine to determine its stiffness values ​​within different load ranges. The testing equipment used was an Instron 5944 universal testing machine or an equivalent model, equipped with a high-precision sensor with a range of 10 N (accuracy not less than ±0.5%). The clamps were pneumatic flat-push clamps with rubber pads on the clamping surfaces to prevent sample slippage and damage. The testing environment was controlled at a temperature of 23℃±2℃ and a relative humidity of 50%±5%. The samples were conditioned in this environment for at least 24 hours before testing.

[0057] During sample preparation, the sling body 1 is cut into a single sample containing complete partitions, with a total length of not less than 60 mm, ensuring that the middle part includes the area to be tested after clamping both ends. If it is necessary to measure the stiffness of a specific area (such as the support area, anchoring area, or transition area) separately, that area can be cut out for testing, and the clamping position should avoid other areas. At least 5 parallel samples should be tested for each sample, and the test results are expressed as mean ± standard deviation.

[0058] The testing procedure is as follows: First, clamp both ends of the sling specimen into the upper and lower clamps, adjusting the clamping distance (gauge length) to 30 mm to ensure the specimen is vertical and free from torsion. Preload 0.01 N to eliminate specimen relaxation and initial bending. Then, continuously load at a constant tensile speed of 50 mm / min up to 12 N, recording the force-displacement curve throughout the process. Repeat the test once for each parallel specimen, and take the average of 5 samples as the final result.

[0059] Stiffness calculation is performed as follows: Initial stiffness K initial The average stiffness is given within the strain range of 0-5%. Calculate the ratio (slope) of the force difference to the displacement difference between the two endpoints of this range. This range corresponds to the minute deformation of the sling under resting conditions. Load stiffness K. load This represents the average stiffness within the strain range of 5%-15%. Calculate the ratio (slope) of the force difference to the displacement difference between the two endpoints of this range. This range corresponds to the deformation range of the sling under high abdominal pressure conditions such as coughing or sneezing. To determine the segmented stiffness within other strain ranges, refer to the above method and calculate the slope at the two endpoints of the corresponding strain range. For the gradual change characteristics of transition zone 3, the local stiffness at each location along the length of transition zone 3 can be measured to reflect the change in stiffness along the length.

[0060] In this test, strain was calculated as the ratio of displacement to the original gauge length (strain = displacement / original gauge length × 100%). The specimen width was 10 mm, the original gauge length was 30 mm, and the loading speed was 50 mm / min.

[0061] The following description is based on specific embodiments:

[0062] Example 1

[0063] This embodiment provides an adaptive mid-urethral suspension system based on a variable stiffness structure:

[0064] The sling body 1 is woven from polypropylene monofilament in one piece. The weaving method is warp knitting of monofilament curled hexagonal shape, which is divided into support area 2, anchoring area 4, and transition area 3.

[0065] Support area 2: 30 mm in length, located in the middle of the sling body 1. It is made of 0.20 mm diameter polypropylene monofilament, woven at a high density of 40 stitches / 10 cm, forming a mesh area of ​​approximately 2.8 mm². 2 After testing, its K... initial 0.5 N / mm (0-5% strain range), K load The strain is 8.0 N / mm (5%-15% strain range). A silicone pad 7 with a thickness of 3 mm, a width of 12 mm, and a length of 25 mm is fixed to the side of the support area 2 facing the urethra using medical-grade silicone adhesive.

[0066] Anchoring Zone 4: Two anchoring zones 4 are symmetrically arranged on both sides of support zone 2. Each zone is 45 mm long. They are made of 0.10 mm diameter polypropylene monofilament, woven at a density of 30 stitches / 10 cm, resulting in a mesh area of ​​approximately 4.0 mm². 2 After testing, its K... initial 0.15 N / mm, K load The strength is 1.5 N / mm. A widened structure 5 is provided at the distal end of the anchoring area 4, on which a channel 6 is opened for surgical puncture instruments to pass through.

[0067] Transition Zone 3: Located between Support Zone 2 and Anchor Zone 4, with a single-sided length of 12 mm. It is woven using polypropylene monofilaments with a diameter of 0.16 mm. Its weaving structure is a gradient density, with the weaving density gradually decreasing from 40 stitches / 10cm to 30 stitches / 10cm in increments of 10 stitches / 10cm. The mesh area is 1.2 mm². 2 The change was from 2.8 mm 2 Gradually increase to 4.0 mm 2 ...After testing, its K... initial 0.3 N / mm, K load It is 2.5 N / mm.

[0068] Example 2

[0069] This embodiment provides another adaptive mid-urethral suspension system based on a variable stiffness structure.

[0070] The sling body 1 is made of polyvinylidene fluoride (PVDF) monofilament crimped into a hexagonal shape and is divided into a support area 2, an anchoring area 4, and a transition area 3.

[0071] Support section 2: 30 mm in length. It is made of 0.18 mm diameter PVDF monofilament, woven at a density of 42 stitches / 10 cm, with a mesh area of ​​approximately 2.0 mm². 2 After testing, its K... initial 0.7 N / mm, K loadThe strength is 12.0 N / mm. A silicone pad with a thickness of 3 mm, a width of 13 mm, and a length of 25 mm is fixed to the side of the support area 2 facing the urethra using medical-grade silicone adhesive.

[0072] Anchoring Zone 4: Each of the two anchoring zones 4 is 45 mm long. It is made of 0.10 mm diameter polypropylene monofilament, woven at a density of 30 stitches / 10 cm, with a mesh area of ​​approximately 3.5 mm². 2 After testing, its K... initial 0.08 N / mm, K load The strength is 2.5 N / mm. A widened structure 5 is provided at the distal end of the anchoring area 4, on which a channel 6 is opened for surgical puncture instruments to pass through.

[0073] Transition Zone 3: 12 mm in length on one side. It is woven using polypropylene and polylactic acid composite monofilaments (0.14 mm in diameter). The weaving density gradually changes from 42 stitches / 10 cm to 30 stitches / 10 cm in increments of 12 stitches / 10 cm, with a mesh area of ​​1.5 mm². 2 The change is from 2.0 mm 2 Gradually change to 3.5 mm 2 After testing, its K... initial 0.35 N / mm, K load It is 4.0 N / mm.

[0074] Example 3

[0075] This embodiment provides a suspender strap made of hybrid materials.

[0076] The sling body 1 is woven in a single-filament hexagonal warp knitting pattern and is divided into a support area 2, an anchoring area 4, and a transition area 3.

[0077] Support section 2: 30 mm in length. It is made of 0.22 mm diameter polypropylene monofilament, woven at a density of 45 stitches / 10 cm, with a mesh area of ​​approximately 2.0 mm². 2 After testing, its K... initial 0.30 N / mm, K load The strength is 5.0 N / mm. The side of the support area 2 facing the urethra is sutured with a silicone pad that is 3 mm thick, 14 mm wide, and 25 mm long.

[0078] Anchoring Zone 4: Each of the two anchoring zones 4 is 45 mm long. It is made of polypropylene monofilament (0.10 mm in diameter), woven at a density of 30 stitches / 10 cm, with a mesh area of ​​approximately 4.0 mm². 2 After testing, its K... initial 0.12 N / mm, K loadThe value is 1.2 N / mm. A widened structure 5 is provided at the distal end of the anchoring area 4, on which a channel 6 is opened for surgical puncture instruments to pass through.

[0079] Transition Zone 3: 12 mm in length on one side. It is woven using a composite monofilament of polypropylene and polyglycolic acid (0.14 mm in diameter). The weaving density gradually changes from 45 stitches / 10 cm to 30 stitches / 10 cm in increments of 15 stitches / 10 cm, with a mesh area of ​​2.0 mm². 2 The change is from 2.0 mm 2 Gradually change to 4.0 mm 2 After testing, its K... initial 0.22 N / mm, K load It is 2.2 N / mm.

[0080] Example 4

[0081] This embodiment provides another adaptive mid-urethral suspension system based on a variable stiffness structure.

[0082] The sling body 1 is woven in a single-filament hexagonal warp knitting pattern and is divided into a support area 2, an anchoring area 4, and a transition area 3.

[0083] Support section 2: 30 mm in length, made of 0.18 mm diameter polypropylene monofilament, woven at a density of 38 stitches / 10 cm, with a mesh area of ​​approximately 2.2 mm². 2 According to tests, K initial 0.25 N / mm, K load The strength is 3.5 N / mm. The side of the support area 2 facing the urethra is covered and fixed with a silicone pad that is 4 mm thick, 15 mm wide, and 30 mm long.

[0084] Anchoring zone 4: 45 mm long on one side, made of 0.10 mm diameter polypropylene monofilament, woven at a density of 30 stitches / 10 cm, with a mesh area of ​​approximately 3.0 mm². 2 After testing, its K... initial 0.12 N / mm, K load The strength is 1.2 N / mm. A widened structure 5 is provided at the distal end of the anchoring area 4, on which a channel 6 is opened for surgical puncture instruments to pass through.

[0085] Transition Zone 3: 12 mm in length on one side, woven with 0.14 mm diameter polyvinylidene fluoride monofilament. The weaving density gradually changes from 38 stitches / 10 cm to 30 stitches / 10 cm in increments of 8 stitches / 10 cm, with a mesh area of ​​0.8 mm². 2 The change was from 2.2 mm. 2 Gradually change to 3.0mm 2 After testing, its K...initial 0.18 N / mm, K load It is 2.0 N / mm.

[0086] Example 5

[0087] This embodiment provides another adaptive mid-urethral suspension system based on a variable stiffness structure, suitable for severe intrinsic sphincter defects.

[0088] The sling body 1 is woven in a single-filament hexagonal warp knitting pattern and is divided into a support area 2, a transition area 3, and an anchoring area 4.

[0089] Support area 2: 32 mm in length, made of 0.25 mm diameter polyvinylidene fluoride monofilament, woven at a density of 40 stitches / 10 cm, with a mesh area of ​​approximately 2.5 mm². 2 After testing, its K... initial 0.70 N / mm, K load The strength is 12.0 N / mm. The side of the support area 2 facing the urethra is covered and fixed with a silicone pad that is 3 mm thick, 13 mm wide, and 27 mm long.

[0090] Anchoring zone 4: 45 mm long on one side, made of 0.10 mm diameter polypropylene monofilament, woven at a density of 25 stitches / 10 cm, with a mesh area of ​​approximately 3.5 mm². 2 After testing, its K... initial 0.12 N / mm, K load The strength is 2.0 N / mm. A widened structure 5 is provided at the distal end of the anchoring area 4, on which a channel 6 is opened for surgical puncture instruments to pass through.

[0091] Transition Zone 3: 12 mm in length on one side, woven with 0.18 mm diameter polypropylene monofilament. The weaving density gradually changes from 40 stitches / 10 cm to 25 stitches / 10 cm in increments of 15 stitches / 10 cm, with a mesh area of ​​1.3 mm². 2 The change was from 2.2 mm. 2 Gradually change to 3.5 mm 2 After testing, its K... initial 0.35 N / mm, K load It is 4.5 N / mm.

[0092] It should be noted that after pre-pressing, the monofilaments are formed into a crimped state. These crimped monofilaments are then woven into a hexagonal mesh structure using a warp knitting process, such as... Figure 3 As shown.

[0093] The specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention in detail. The above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An adaptive mid-urethral suspension system based on a variable stiffness structure, comprising a sling body (1), characterized in that, The sling body (1) includes: The support area (2) is located in the middle of the sling body (1); the initial stiffness of the support area (2) is 0.1-0.8 N / mm and the load stiffness is 0.2-12.0 N / mm; a silicone pad (7) is fixedly provided on the surface of the support area (2) near the urethra. Anchoring areas (4) are symmetrically arranged on both sides of the support area (2); the initial stiffness of the anchoring areas (4) is 0.05-0.4 N / mm and the load stiffness is 0.5-2.5 N / mm; The transition zone (3) is located between the support zone (2) and the anchoring zone (4). The initial stiffness of the transition zone (3) is 0.08-0.5 N / mm and the load stiffness is 1.0-5.0 N / mm. The stiffness of the transition zone (3) is between that of the support zone (2) and the locking zone (4).

2. The adaptive mid-urethral suspension system based on a variable stiffness structure according to claim 1, characterized in that, The diameter of the monofilament constituting the support area (2) is 0.15-0.25 mm, and its material is one of polypropylene, polyvinylidene fluoride, or polyester; the support area (2) has a high-density braided structure with a braiding density of 35-50 needles / 10cm and a mesh area of ​​2.0-3.0 mm. 2 .

3. The adaptive mid-urethral suspension system based on a variable stiffness structure according to claim 1, characterized in that, The diameter of the monofilament constituting the anchoring area (4) is 0.06-0.12 mm, and its material is one or a mixture of two of the following: polypropylene, polypropylene composite material coated with polylactic acid, or polyvinylidene fluoride; the anchoring area (4) is a low-density woven structure with a weaving density of 20-30 needles / 10cm and a mesh area of ​​3.0-4.5 mm. 2 .

4. The adaptive mid-urethral suspension system based on a variable stiffness structure according to claim 1, characterized in that, The diameter of the monofilament constituting the transition zone (3) is 0.10-0.18 mm, and its material is one of polypropylene, polyvinylidene fluoride, polypropylene and polylactic acid composite, or polypropylene and polyglycolic acid composite; the transition zone (3) is a gradually decreasing density braided structure, and along the direction from the support zone (2) to the anchoring zone (4), its braiding density gradually decreases by 5-15 stitches / 10cm, and the mesh area is 0.5-2.0 mm. 2 The change gradually increases, and the weaving density and mesh area at any position in the transition zone (3) are between or equal to the corresponding parameters of the support zone (2) and the anchoring zone (4).

5. The adaptive mid-urethral suspension system based on variable stiffness according to claim 2, characterized in that, The diameter of the monofilament constituting the support area (2) is 0.18-0.25 mm, and its material is polypropylene or polyvinylidene fluoride; the weaving density of the support area (2) is 38-45 stitches / 10cm, and the mesh area is 2.0-2.5 mm. 2 .

6. The adaptive mid-urethral suspension system based on variable stiffness according to claim 3, characterized in that, The monofilament constituting the anchoring area (4) has a diameter of 0.10 mm and is made of either polypropylene or a polypropylene composite material coated with polylactic acid. The anchoring area (4) has a low-density braided structure with a braiding density of 25-30 needles / 10cm and a mesh area of ​​3.0-4.0 mm. 2 .

7. The adaptive mid-urethral suspension system based on a variable stiffness structure according to claim 4, characterized in that, The diameter of the monofilament constituting the transition zone (3) is 0.14-0.18 mm, and its material is one of polypropylene and polylactic acid composite material or polypropylene and polyglycolic acid composite material; the transition zone (3) is a gradually decreasing density braided structure, and along the direction from the support zone (2) to the anchoring zone (4), its braiding density gradually decreases by 8-15 stitches / 10cm, and its mesh area is 0.8-2.0 mm. 2 The amount of change gradually increases.

8. The adaptive mid-urethral suspension system based on a variable stiffness structure according to claim 1, characterized in that, The distal end of the anchoring area (4) is provided with a widening structure (5), and the widening structure (5) has a channel (6) for surgical instruments to pass through.

9. A method for fabricating an adaptive mid-urethral suspension system based on a variable stiffness structure according to any one of claims 1-8, characterized in that, The preparation method includes a personalized customization step and a sling body manufacturing step; The personalization process includes: Acquire target patient data; Based on the data, a mechanical model of the patient is constructed, and the stiffness distribution parameters of the required sling body are calculated. The weaving parameters of the sling body are determined based on the stiffness distribution parameters. The weaving parameters include the monofilament diameter, weaving density, and mesh area of ​​the support area, anchoring area, and transition area, respectively. The steps for manufacturing the sling body include: preparing the sling body using a variable weaving process according to the weaving parameters.

10. A method for fabricating an adaptive mid-urethral suspension system based on a variable stiffness structure according to claim 9, characterized in that, The manufacturing steps for the sling body include: Prepare monofilaments: According to the braiding parameters, prepare monofilaments to form the support zone, anchoring zone, and transition zone respectively. The monofilaments forming the support zone have a diameter of 0.15-0.25 mm and are made of polypropylene, polyvinylidene fluoride, or polyester. The monofilaments forming the anchoring zone have a diameter of 0.06-0.12 mm and are made of polypropylene, polypropylene composite material coated with polylactic acid, or polyvinylidene fluoride, or a mixture of two of these materials. The monofilaments forming the transition zone have a diameter of 0.10-0.18 mm and are made of polypropylene, polyvinylidene fluoride, polypropylene and polylactic acid composite, or polypropylene and polyglycolic acid composite. Setting up the knitting equipment: Install the prepared monofilaments for each area onto the warp knitting machine, set the knitting program so that the knitting density of the support area is 35-50 stitches / 10cm and the mesh area is 2.0-3.0 mm. 2 The weaving density of the anchoring area is 20-30 stitches / 10cm, and the mesh area is 3.0-4.5 mm. 2 The transition zone, along the direction from the support zone to the anchoring zone, gradually decreases in knitting density by a variation of 5-15 stitches / 10cm, with a mesh area ranging from 0.5-2.0 mm. 2 The change gradually increases, and the weaving density and mesh area at any position in the transition zone are between the corresponding parameters of the support zone and the anchoring zone; Weaving: Start the warp knitting machine to weave. During the weaving process, the machine automatically switches between monofilaments of different diameters according to the program to obtain a continuous suspender fabric. Post-processing: The suspender fabric is heat-set, cleaned, and dried. Cutting and shaping: The post-processed suspender fabric is cut into the preset size, silicone pads are fixedly installed in the support area, and a widened structure and channel are formed at the far end of the anchoring area. After sterilization, the finished suspender body is obtained.

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